// Copyright 2018 The ksonnet authors
//
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.

package k8s

import (
	"github.com/pkg/errors"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
)

// FlattenToV1 expands any List-type objects into their members, and
// coerces everything to v1.Unstructured.
func FlattenToV1(objs []runtime.Object) ([]*unstructured.Unstructured, error) {
	ret := make([]*unstructured.Unstructured, 0, len(objs))
	for _, obj := range objs {
		switch o := obj.(type) {
		case *unstructured.UnstructuredList:
			for i := range o.Items {
				ret = append(ret, &o.Items[i])
			}
		case *unstructured.Unstructured:
			ret = append(ret, o)
		default:
			return nil, errors.New("Unexpected object type")
		}
	}
	return ret, nil
}
